Hydraulic cylinder assembly

ABSTRACT

A hydraulic cylinder comprising an assembly of easily manufactured and conveniently assembled components.

United States Patent Herbert Z. Langlaud Topeka, Kans.;

John R. Plate, Milwaukee, Wis.

Apr. 4, 1969 Aug. 10, 197 1 Allis-Chalmers Manufacturing Company Milwaukee, Wis.

inventors App]. No. Filed Patented Assignee HYDRAULIC CYLINDER ASSEMBLY 7 Claims, 5 Drawing Figs.

US. Cl 92/169, 92/165, 292/256167 Fl6j 13/10 Field of Search 285/321,

DIG. 18;92/l28, 165168, 171;220/55 O; 292/256.67, 256.65

[56] References Cited UNITED STATES PATENTS 1,734,236 10/1929 Smith et al .1 285/321 X 2,724.368 10/1955 Miller 92/128 2,997,026 8/1961 Zimmerer.. 92/128 3,421,786 1/1969 Panigati 92/128 UX 3,334,937 8/1967 Jofeh 292/256.67

Primary Examiner-Martin P. Schwadron Assistant Examiner-Allen Ostrager Auorneys-Arthur L. Nelson, Robert B. Benson and Kenneth C. McKivett ABSTRACT: A hydraulic cylinder comprising an assembly of easily manufactured and conveniently assembled components.

HYDRAULIC CYLINDER ASSEMBLY This invention relates to a hydraulic cylinder and more particularly to a hydraulic cylinder including components which are easily and economically manufactured and conveniently assembled.

Over the years, the motor vehicle has been used as a vehicle in which the motor itself is used essentially as a motive means. The motor vehicle of today is becoming increasingly sophisticated and the power functions required of the motor are increasing. One of the more common ways of using the engine which drives the vehicle is to also drive a hydraulic pump which serves as a source of power for fluid-operated systems for related auxiliary functions on a motor vehicle. The increased number of hydraulic systems required of the motor vehicle today correspondingly requires an increased number of hydraulic actuators to perform these functions. Accordingly, the economy in manufacturing and assembling these increased number of hydraulic actuators becomes increasingly important. This invention provides a means for economy of manufacturing and simplicity of assembly and disassembly in case of repair.

It is an object of this invention to provide a hydraulic actuator constructed of basic components conveniently assembled.

It is another object of this invention to provide a hydraulic cylinder including a barrel, a head and piston with an expansible retainer ring and expanding means for fastening the cylinder assembly.

It is a further object of this invention to provide a hydraulic cylinder having a barrel receiving a head with an expandable retainer ring locking means locking the cylinder assembly.

The objects of this invention are accomplished by using a barrel having a machined internal surface and a head for each end ofthe barrel mating the internal dimensions ofthe barrel. A retainer ring is seated within the head and expanded by expanding elements to a position within an internal groove of the barrel and an external recess of the head. The expanding means radially expands the retainer ring into the groove of the barrel preventing relative axial movement between barrel and the head.

A modification of the device provides for a stepped internal diameter of the barrel to accommodate the head on one end, and a sleeve closed at one end received in the opposite end of the barrel. The radial portion joining the two diameter surfaces of thebarrel forms a stop for limiting the axial movement of the sleeve relative to the barrel.

The preferred embodiments of this invention are illustrated on the attached drawing and will be described in the subsequent paragraphs.

FIG. 1 illustrates a hydraulic cylinder comprising a sleeve and a barrel assembly;

FIG. 2 illustrates an enlarged fragmentary cross section view of the fastening means between the head and the barrel;

FIG. 3 is an end view of the retainer ring in which the retainer ring has recessed portions on its internal periphery to accept a lock screw for expanding the ring;

FIG. 4 is an end view of FIG. 1 showing the fastening means for the head and barrel; and

FIG. 5 is a cross section view ofa modification ofa cylinder to provide double-acting operation.

Referring to the drawing, FIG. 1 shows a hydraulic cylinder in cross section. The head 1 forms a clevis 2 for connection to a device being actuated. The head 1 is welded to the sleeve 3 by means of a weldment 4. The sleeve 3 extends axially into pressurizing chamber 5 of the cylinder 6 and forms a recess 7 for receiving a snapring 8. The snapring 8 forms a stop for the sleeve 3 in its extended position as shown by the phantom lines 9. The barrel 10 receives the sleeve 3 and is formed with the annular grooves 11 and 12. The grooves 11 and 12 receive the seals 13 and 14, respectively. The barrel 10 is constructed with a fitting 15 forming a fluid passage 16 in communication with chamber 5.

The head 17 also defines a clevis 18. The head 17 forms annular recesses 19 and 20. The annular recess 20 receives a seal 21. The recess 19 is positioned axially aligned with the groove 22. The groove 22 and recess 19 receives the retainer ring 23. The retainer ring 23 is expanded into the groove 22 means of plurality lock screws 24.

Referring to FIG. 2, the fastening means is shown enlarged to more clearly illustrate the relative position of the components. The sleeve 3 receives the snapring 8. The sleeve 3 is shown abutting the end of the head 17. The head 17 receives the O-ring seal 21 and the lathe cut seal 25. The O-ring seal 21 and seal 25 engage the inner periphery with the barrel.

The head also defines the recess 19 which receives the retainer ring 23. The lock screw 24 is shown expanding the retainer ring 23 to lock the assembly. The phantom view 26 also shows the lock screw 24 in which the retainer ring is permitted to contract inwardly into the recess 19.

The lock screw 24 includes a threaded portion 27 which threadedly engages internal threading 28 of the opening 29. The forward end of the screw includes a conical surface 30 of approximately 30 angle adjoining a cylindrical portion 31 intermediate the conical portion 30 and threaded portion 27. A radial facing 32 is also formed on the screw 24 between the threaded portion 27 and the cylindrical portion 31.

FIG. 3 illustrates a retainer ring 23 cut at 33 to permit expansion and contraction of the ring. The plurality of recessed seats 34 are provided to partially receive the conical end 30 of the screws 24 to align the ring and prevent interference between the ring and screws when the screws are tightened. The symmetrical positioning of the screws is also necessary for uniform expansion of the ring when the screws are screwed in and also to prevent the retainer ring 23 from rotating within the assembly once the ring is expanded.

FIG. 4 illustrates the end view ofa hydraulic cylinder shown in FIG. I. The fluid entrance fitting 15 is fastened to the barrel 10. The clevis 18 provides a means for fastening the cylinder to means which are actuated. The head 17 is fastened to the barrel 10 as the lock screws 24 are screwed into the openings 29.

Referring to FIG. 5 a modification is illustrated. Modification shows a double-acting hydraulic cylinder in which the base end 35 is shown in cross section and received within the barrel 36. The base end 35 defines a recess 37 which receives a seal 38. The base end also forms a recess 39 which is axially aligned with the groove 40 in the barrel 36. A snapring is received within the recess 39 and the groove 40 and locks the base end 35 to the barrel 36 in a permanent assembly. It is understood that this end of the hydraulic cylinder might be constructed as the opposite end which will be subsequently described.

The barrel 36 is provided with a fitting 41 providing a passage 42 to transmit the flow of pressurized fluid to and from the pressurized chamber 43. The pressurized chamber is defined by the head 35, the barrel 36 and the piston 44. The piston 44 is fitted with a seal 45 and connected to a rod 46. The rod 46 is fastened to the piston 44 by the nut 47. The end of the rod 46 abuts the end of head 35 when the piston is in its extreme right-hand position.

The barrel is fitted with a fitting 48 forming a passage 49 to transmit fluid to and from the pressurizing chamber 50 defined by the piston 44, the barrel 36 and the head 51. The head 51 defines an annular recess 52 and an annular recess 53. An annular recess 53 is aligned with the groove 54in barrel 36 and receives the retainer ring 55. The head 51 defines a central opening 56 which receives the piston rod 46. The head 51 further defines an annular recess 60 and an annular recess 61. The recess 60 receives the seal 62 and the recess 61 receives the seal 63.

The head is further provided with a plurality of threaded openings 64 for receiving lock screws 65. A lock screw 65 as shown is similar to the one described in FIG. 2 and provides the function of expanding the retainer ring 55 to a position in which it rests partially within the groove 54 and the recess 53 to lock the head 51 and barrel 36 in a fixed relative axial position. The hydraulic cylinder shown in P16. 5 is a double acting cylinder and is operated by receiving pressurized fluid to either the passage 42 or 49 while the fluid which is not under pressure in the opposing chamber is discharged through one of the passages 42 or 49. The operation of the device will be described in the following paragraphs.

Referring to FIG. 1, the head 17 and the head 1 are readily assembled to the barrel by inserting the head 1 into the barre] 10. The snapring 8 is positioned in the annular groove 7 to prevent the sleeve 3 on head 1 from being withdrawn completely from the barrel 10. It is understood that the sleeve 3 and the clevis 2 are welded together prior to insertion into the barrel 10.

The head 17 is then fitted with a seal 21 and the retainer ring 23 in the respective recesses 20 and 19. The head 17 is then positioned in the end of the barrel 10 so that the recess 19 and the groove 22 are in alignment. Then the lock screws 24 which threadedly engage their respective openings 28 are screwed into the openings causing the conical surface 30 to expand the retainer ring 23 so that it rests partially within the recess 19 and the groove 22. This will permanently lock the head in the end of the barrel 10 and the assembly of the cylinder is complete. The cylinder as shown in FIG. 1 is a single-acting cylinder, in other words the pressurized chamber 5 operates to expand the head 1 relative to the barrel 10 until the snapring 8 engages the bevel surface 70 as shown in phantom of FIG. 1. The head 1 is returned by some other means external of the cylinder as shown.

Referring to FIG. 5, a modification is illustrated in which the base end 35 is fitted to a barrel 36. This is accomplished in a manner whereby the seal 38 is positioned in the recess 37 and then the snapring 140 is positioned in a groove 39. The base end 35 is then positioned in the end of the barrel 36 and moved axially until the recess 39 is in alignment with the groove 40 and the snapring 140 locks the two elements in a fixed nonmovable axial relationship.

The head 51 is then fitted with the seal 71 which is received within the groove 52. The recess 53 then receives the retainer ring 55. The seal 62 and 63 are then positioned in the groove 60 and 61 prior to inserting the connecting rod 46 in the opening 56. 1

The piston 44 is then positioned in the end of the barrel 36 and the head 51 is subsequently positioned in the barrel and moved axially until the recess 53 and groove 54 are in axial alignment. When this exists, the lock screws 65 are tightened in their respective openings and the retainer ring is expanded to move partially within the groove 54 which locks the head 51 in the barrel 36. This completes the assembly of the cylinder as shown and the cylinder is then ready for use in the hydraulic system.

The embodiments of the invention in which we claim an exclusive property or privilege are defined as follows:

1. A hydraulic cylinder comprising a barrel defining an annular peripheral surface adjoining radial lateral surfaces forming at least one internal annular groove on the end portion thereof, a head having a seal received within the one end of said barrel defining an annular peripheral surface adjoining radial lateral surfaces forming at least one annular recess, a split retainer ring defining a rectangular-shaped cross section with at least three equal angularly spaced recessed seats on its inner periphery and received in said annular recess, expanding means engaging said recessed seats and biasing said retainer ring partially within said annular groove to axially lock the said head with said barrel, a piston reciprocally positioned in said barrel, and means for limiting the range of axial movement of said piston relative to said barrel.

2. A hydraulic cylinder as set forth in claim 1 wherein said head defines two annular recesses, said seal received in one of said annular recesses to hydraulically seal said head in said barrel.

3. A hydraulic cylinder as set forth in claim 1 wherein said barrel defines an internal flange operating as a piston stop, said piston defines a sleeve received in said barrel with said sleeve extending axially from an external closed portion of said piston, the inner end of said sleeve defining an annular recess, a snapring positioned in said annular recess engaging said stop in said barrel to limit the extended position of said piston relative to said barrel, said sleeve engaging said head to define the contracted position of said piston relative to said barrel.

4. A hydraulic cylinder as set forth in claim 1 wherein said expanding means expanding said retainer ring comprises a plurality of lock screws angularly spaced on a common radius in said head, said screws define a conical surface engaging said recessed seats on the inner periphery of said retainer ring for expanding said retainer ring partially into said recess in said head and said groove in said barrel to thereby lock the cylinder of said pin.

5. A hydraulic cylinder as set forth in claim 4 wherein said expanding means includes at least three lock screws having cone shaped end surfaces for expanding said retainer ring.

6. A hydraulic cylinder as set forth in claim 1 wherein said barrel defines an annular recess in each end of said barrel, said cylinder defines a double acting cylinder including a base end defining two annular recesses, a retainer ring partially received in one of said annular recesses and one of said grooves in said barrel to lock said base relative said barrel when said cylinder is assembled, a seal positioned in a second annular'recess of said base end to provide a hydraulic sealing means, a head positioned in the opposite end of said barrel defining a seal recess and retainer ring recess and a seal and a retainer ring received in said recesses, said expanding means expanding said retainer rings to lock said base end and said head relative to said barrel, a piston positioned in said barrel having a connecting rod extending through a central opening in said head to thereby provide a double acting hydraulic cylinder.

7. A hydraulic cylinder as set forth in claim 1 wherein said head includes said retainer ring defining an axial surface on its inner periphery, a plurality of lock screws for expanding said retainer ring comprising a conical surface for expanding said retainer ring to partially lie within the recess of said head and the groove of said barrel, a locking surface of cylindrical configuration on said screws engaging said axial surface on the inner periphery of said retainer ring for maintaining the expanded position of said retainer ring to thereby lock said head relative to said barrel when said hydraulic cylinder is assembled. 

1. A hydraulic cylinder comprising a barrel defining an annular peripheral surface adjoining radial lateral surfaces forming at least one internal annular groove on the end portion thereof, a head having a seal received within the one end of said barrel defining an annular peripheral surface adjoining radial lateral surfaces forming at least one annular recess, a split retainer ring defining a rectangular-shaped cross section with at least three equal angularly spaced recessed seats on its inner periphery and received in said annular recess, expanding means engaging said recessed seats and biasing said retainer ring partially within said annular groove to axially lock the said head with said barrel, a piston reciprocally positioned in said barrel, and means for limiting the range of axial movement of said piston relative to said barrel.
 2. A hydraulic cylinder as set forth in claim 1 wherein said head defines two annular recesses, said seal received in one of said annular recesses to hydraulically seal said head in said barrel.
 3. A hydraulic cylinder as set forth in claim 1 wherein said barrel defines an internal flange operating as a piston stop, said piston defines a sleeve received in said barrel with said sleeve extending axially from an external closed portion of said piston, the inner end of said sleeve defining an annular recess, a snapring positioned in said annular recess engaging said stop in said barrel to limit the extended position of said piston relative to said barrel, said sleeve engaging said head to define the contracted position of said piston relative to said barrel.
 4. A hydraulic cylinder as set forth in claim 1 wherein said expanding means expanding said retainer ring comprises a plurality of lock screws angularly spaced on a common radius in said head, said screws define a conical surface engaging said recessed seats on the inner periphery of said retainer ring for expanding said retainer ring partially into said recess in said head and said groove in said barrel to thereby lock the cylinder of said pin.
 5. A hydraulic cylinder as set forth in claim 4 wherein said expanding means includes at least three lock screws having cone shaped end surfaces for expanding said retainer ring.
 6. A hydraulic cylinder as set forth in claim 1 wherein said barrel defines an annular recess in each end of said barrel, said cylinder defines a double acting cylinder including a base end defining two annular recesses, a retainer ring partially received in one of said annular recesses and one of said grooves in said barrel to lock said base relative said barrel when said cylinder is assembled, a seal positioned in a second annular recess of said base end to provide a hydraulic sealing means, a head positioned in the opposite end of said barrel defining a seal recess and retainer ring recess and a seal and a retainer ring received in said recesses, said expanding means expanding said retainer rings to lock said base end and said head relative to said barrel, a piston positioned in said barrel having a connecting rod extending through a central opening in said head to thereby provide a double acting hydraulic cylinder.
 7. A hydraulic cylinder as set forth in claim 1 wherein said head includes said retainer ring defining an axial surface on its inner periphery, a plurality of lock screws for expanding said retainer ring comprising a conical surface for expanding said retainer ring to partially lie within the recess of said head and the groove of said barrel, a locking surface of cylindrical configuration on said screws engaging said axial surface on the inner periphery of said retainer ring for maintaining the expanded position of said retainer ring to thereby lock said head relative to said barrel when said hydraulic cylinder is assembled. 